fix(agent-debug): stream execution traces with platform mocks and coverage

web/src/app/infra/http/BackendClient.ts

@@ -1,4 +1,5 @@
 import { BaseHttpClient, type RequestConfig } from './BaseHttpClient';
+import type { DebugExecutionEvent } from '@/app/infra/entities/api/agent-debug';
 import {
   ApiRespProviderRequesters,
   ApiRespProviderRequester,
@@ -288,6 +289,7 @@ export class BackendClient extends BaseHttpClient {
       conversation_id?: string;
       actor?: Record<string, unknown>;
       subject?: Record<string, unknown>;
+      mock?: Record<string, unknown>;
     },
   ): Promise<{
     event_id: string;
@@ -303,6 +305,53 @@ export class BackendClient extends BaseHttpClient {
     return this.post(`/api/v1/agents/${uuid}/debug`, payload);
   }
 
+  public async streamDebugAgent(
+    uuid: string,
+    payload: Parameters<BackendClient['debugAgent']>[1],
+    onResult: (event: DebugExecutionEvent) => void,
+    signal: AbortSignal,
+  ): ReturnType<BackendClient['debugAgent']> {
+    let offset = 0;
+    let result: Awaited<ReturnType<BackendClient['debugAgent']>> | undefined;
+    let failure: { code: string; msg: string } | undefined;
+    const consume = (text: string) => {
+      let end: number;
+      while ((end = text.indexOf('\n', offset)) !== -1) {
+        const line = text.slice(offset, end).trim();
+        offset = end + 1;
+        if (!line) continue;
+        const frame = JSON.parse(line);
+        if (frame.kind === 'result') onResult(frame.data);
+        else if (frame.kind === 'completed') result = frame.data;
+        else if (frame.kind === 'error') failure = frame;
+      }
+    };
+    const response = await this.instance.post<string>(
+      `/api/v1/agents/${uuid}/debug/stream`,
+      payload,
+      {
+        adapter: 'xhr',
+        responseType: 'text',
+        timeout: 0,
+        signal,
+        headers: { Accept: 'application/x-ndjson' },
+        transformResponse: [(data) => data],
+        onDownloadProgress: (progress) => {
+          const xhr = progress.event?.target as XMLHttpRequest | undefined;
+          if (xhr?.status === 200) consume(xhr.responseText);
+        },
+      },
+    );
+    consume(response.data);
+    if (failure) throw failure;
+    if (!result)
+      throw {
+        code: 'runner_protocol_error',
+        msg: 'Debug stream ended before completion',
+      };
+    return result;
+  }
+
   public getGeneralPipelineMetadata(): Promise<GetPipelineMetadataResponseData> {
     // as designed, this method will be deprecated, and only for developer to check the prefered config schema
     return this.get('/api/v1/pipelines/_/metadata');